If not, I'd call that a failure of anti-trust law, not UBI.
That's the economy reorienting itself around the new demand landscape. Those price spikes are the signal to producers to ramp up supply, which should push the price back down over time.
Inflation is highly problematic when it spirals. Events like collapse of trust in a currency or government can result in runaway inflation, which is a disaster by all accounts. A one-time price spike caused by a one-time abrupt shift in demand is a very different scenario. Assuming the UBI is higher than the prices increases on necessities, we've successfully redistributed wealth and made those people better able to afford necessities, despite the fact that they cost x% more.
I said "mostly" because there can be things like supply shocks... but I guess that means less stuff, so maybe even that isn't an exception.
UBI, like any government spending, needs to be paid for. By taxes or financial disaster. I prefer taxes, personally.
One wonders though what impact that will have on society — so much additional free time. More television binging? I hope not.
Our own psychology aside, people need to work because at present robots cannot make all the stuff we want. So if we (society as a whole) want all this stuff, then we need to work.
We have a duty to treat our fellow humans with dignity and humanity. I'm not sure that extends to providing for those who can work but won't, though - not when there's work that society as a whole needs done.
I think there needs to be a pretty fundamental shift in society for us to continue to function if, for example, everyone was essentially on welfare. Not sure what they are supposed to all be doing in the "Star Trek universe" for example. Somehow "Logan's Run" comes to mind — you know, if we actually still got together with each other. ;-)